This invention relates to an internal combustion engine and more particularly to an improved exhaust control device for such engines and an arrangement for operating the exhaust control valve of this type of engine.
In many types of engine applications, particularly those employing two cycle engines, it has been proposed to employ an exhaust control valve that controls the timing of opening and closing of the exhaust valve and/or the effective compression ratio of the engine. By changing the position of the exhaust control valve, it is possible to operate at higher compression ratios under low, and mid-range load and to reduce the compression ratio to extend the engine life under high loads. In addition, the variation in the timing of the exhaust port opening and closing can be adjusted for other purposes such as exhaust emission control or the like.
This type of control is frequently used on vehicles such as motorcycles that are very compact in nature and do not afford significant room for external mounting of accessories or controls directly on the engine. Therefore, it has been the practice to provide a wire transmitter that is operated by a remote operator and which controls the exhaust control valve. However, the use of such motion transmitting mechanisms can induce inaccuracies in the system.
It is, therefore, a principle object of this invention to provide an improved operating mechanism for the exhaust control valve of an internal combustion engine.
It is a further object of this invention to provide an improved exhaust control valve for an internal combustion engine and drive mechanism therefore which can be conveniently mounted on the engine without interference or excess spacial requirements.
It is a further object of this invention to provide an improved exhaust control valve operator that can be easily mounted on the engine.